1. Field of the Invention
The present invention pertains to a method and apparatus for the production of bio-fuels and related compounds including, but not limited to, ethanol. More particularly, the present invention pertains to a microbial seeding system that can be used in the production of bio-fuels, either as a stand-alone process or as part of an existing fermentation system.
2. Brief Description of the Prior Art
As demand for fossil fuel increases, and supply decreases, the costs associated with such fossil fuels can be significant. Additionally, many believe that consumption of fossil fuels negatively impacts the environment by contributing to global warming. Thus, an effort has been underway to find alternative energy sources that can act as a replacement for conventional fossil fuels.
Much attention has focused on bio-fuels as a possible alternative to fossil fuels. Generally, bio-fuels are solid, liquid or gaseous fuels obtained from relatively recently lifeless or living biological material. By contrast, fossil fuels are derived from long-dead biological material. One such bio-fuel that has received a great deal of attention is ethanol, a primarily plant-based fuel which can be produced from organic sources such as sugar cane, corn, waste paper. Ethanol can also be produced from grains like wheat or sorghum.
Ethanol, also known as ethyl alcohol, is a volatile, flammable, colorless liquid having a wide variety of uses including, but not limited to, as a fuel. For example, ethanol has a long history as a fuel for heat and light, and also as a fuel and/or fuel additive for internal combustion engines. When added to gasoline, ethanol reduces volatile organic compound and hydrocarbon emissions, carcinogenic benzene and butadiene emissions, and particulate matter emissions from internal combustion engines. Ethanol is also widely used as a solvent of substances intended for human contact or consumption. In chemistry, ethanol is both an essential solvent and a feedstock for the synthesis of other products, as well as a fuel to power direct-ethanol fuel cells (DEFC) in order to produce electricity.
Although ethanol can be produced via the hydration of ethylene, it is commonly produced biologically through the process of culturing yeast under certain desired conditions (this process is commonly referred to as fermentation). When certain species of yeast (for example, Saccharomyces cerevisiae) metabolize sugar, the yeast can produce ethanol and carbon dioxide. Ethanol can also be produced biologically from starchy materials such as cereal grains; however, in such cases, the starchy material must first be converted into sugar(s).
Feed stocks for the production of ethanol can include, but are not limited to, sugarcane juice, sugarcane syrup, molasses, bagasse, corn, fruit juice and concentrates, purified sugars such as sucrose, glucose, fructose, maltose, and syrup mixtures containing simple sugars such as those found in drink syrups.
Existing processes for the production of ethanol have proven to be inefficient and expensive, and frequently require a large amount of space. Thus, there is a need for a seeding process that can be used to improve overall efficiency, while reducing costs and space requirements, associated with conventional ethanol production processes.